Organic psychiatry Flashcards
Define delirium
An acute and transient state of global brain dysfunction with clouding of consciousness. The patient is not fully aware or ‘in touch’ with their environment. It is a sign that something is physically wrong.
Name five risk factors for delirium
- Old age,
- Pre-existing physical or mental illness
- Substance misuse
- Malnutrition
- Polypharmacy
In delirium, behavioural changes usually take one of two forms. What are these?
- Hyperactivity, agitation, agression
- Hypoactivity, lethargy, stupor, drowsiness and withdrawal
How does the course of delirium differ to dementia?
-The course of delirium is short and fluctuates though out the day; whereas dementia is slowly progressive and lifelong.
Name two medical causes of delirium
Anti-cholinergics and opiates
What CNS pathology can cause delirium?
Raised ICP
What metabolic pathology can cause delirium?
Liver failure, renal failure and electrolyte imbalance
What are the infective causes of delirium?
Septicaemia, encephalitis, UTIs
Name one nutritional cause of delirium
Thiamine deficiency i.e. Wernicke’s Encephalopathy
What endocrine abnormality in diabetics can precipitate delirium?
Hypoglycaemia
What is Huntington’s disease?
Huntington’s disease is an autosomal dominant disease characterised by chorea and dementia.
What trinucleotide repeat causes Huntington’s?
A CAG repeat on the Huntington gene of chromosome 4.
Prion diseases are rare disorders characterised by rapidly progressive neurological and psychiatric symptoms. What’s the main prion disease to affect humans?
Creutzfeldt-Jakob disease (CJD)
What is the cause of variant CJD?
Eating BSE-infected beef. (BSE = Bovine spongiform encephalopathy)
What’s the most common form of CJD?
Sporadic CJD. (The cause of this type is unknown).
What is the main risk factor for Alzheimer’s disease?
Age
What is the cause of familial early onset Alzheimer’s disease?
It is due to rare autosomal dominant gene mutations that cause an increase in beta-amyloid
Name the genes on which mutations occur that can cause familial early onset dementia
Presenilin 1 gene
Presenilin 2 gene
Beta-amyloid precursor protein (APP) gene
Which gene is associated with late onset Alzheimer’s disease? That is >65 yrs
Apo-lipo-protein E4 allele
The cause of AD is multifactorial. What other factors play a role in development of Alzheimer’s?
Vascular risk factors such as hypertension, low IQ/poor educational level and head injury
What are the four key pathological features of Alzheimer’s?
1) Cortical atrophy due to neuronal loss
2) Plaque formation
3) Intracellular neurofibrillary tangles
4) Cholinergic loss
What are the NFTs made of in Alzheimer’s?
Abnomal (hyperphosphorylated) tau protein
What four A’s describe the clinical presentation of Alzheimer’s disease?
Amnesia
Aphasia
Agnosia
Apraxia
What is the word used to describe the inability to recognise faces?
Prosopagnosia
What is the cause of vascular dementia?
Vascular dementia is due to infarcts caused by thrombo-emboli or arteriosclerosis
What are the risk factors for vascular dementia (VD)?
They are the same as the risk factors for stroke e.g. older age, male gender, smoking, hypertension, diabetes, hypercholesterolaemia and atrial fibrillation.
What are the three main features of pathology in VD?
Arteriosclerosis, cortical ischaemia and infarction
How do you describe the clinical presentation of vascular dementia?
It has a step-wise progression
What are Lewy bodies?
Lewy bodies are eosinophilic intracytoplasmic neuronal structures composed of alpha-synuclein with ubiquitin
In Parkinson’s disease, lewy bodies are found in the brainstem. Where are they found in addition to the brainstem in dementia with lewy bodies?
Cingulate gyrus and neocortex
What symptoms should alert you to the possibility of dementia with lewy bodies?
- Fluctuating confusion with variations in levels of alertness
- vivid visual hallucinations (often people and animals)
- Spontaneous (new) parkinsonian signs
Dementia with Lewy bodies can sometimes resemble delirium. Why is this dangerous?
Because prescription of antipsychotics can cause death due to neuroleptic sensitivity in lewy body dementia.
Recurrent falls, syncope and autonomic instability is associated with which type of dementia?
Dementia with Lewy bodies
What drugs can be used to slow the progression of Alzheimer’s and Lewy body dementia? Give two examples
Acetylcholinesterase inhibitors (ACIs) e.g. Rivastigmine and Donepezil
